Modular rail systems, rail systems, mechanisms, and equipment for devices under test

ABSTRACT

The systems, apparatuses, and methods herein can provide a multi-site positioning mechanism suitable for long-term testing of a device(s) under test (DUT) (e.g. semiconductor wafers) across a range of temperatures with or without a controlled environment. The systems, apparatuses, and methods herein include mounting components, mechanisms, and structures that can provide excellent mechanical stability, permit relatively close working distance optics with high resolution, enable fine positioning at elevated temperature in a controlled environment with minimal thermal perturbation. The systems, apparatuses, and methods herein can be provided with modularity, for example as modular with rails and test sites that can be easily added or removed, and that can permit access to probe modules in a densely packed array.

FIELD

This disclosure generally relates to a multi-site precision positioningmechanism, and more particularly, an apparatus for positioning multipleprobe arrays for devices under test (DUT), e.g. the testing ofsemiconductor devices in a semiconductor wafer, over a wide temperaturerange.

BACKGROUND

Semiconductor circuit elements continue to get smaller. Smallertechnologies can require larger test sample sizes and lower stress,longer duration tests.

With smaller devices also come manufacturing pressures to reduceelectrical contact pad sizes. Smaller contact pads can require greaterprobe positioning accuracy, both in XY and in Z. Probe technologiesdesigned for smaller pads can also have a smaller margin of error in Zovertravel before they are damaged. A result may be small mechanicalperturbations, which may not be a problem with relatively larger pads,e.g. 100 or 200 μm sized pads, but can cause probes to miss their padswith relatively smaller pads, e.g. 30 or 40 μm sized pads, or can evendamage probes designed for smaller pads.

In U.S. Pat. No. 6,011,405, XY position of sites are determined bycrossed rods. Arrays have the disadvantage of moving multiple sites witheach rod. Site crosstalk makes fine adjustment a tedious, iterativeprocess. Stiffness of the rods is an issue, both vertically andlaterally. Low vertical stiffness can cause the probes to sag in themiddle. Accidental application of force to the top of the array candamage probe modules. Low lateral stiffness can cause the rod to curveduring adjustments from friction at the sites. Stresses built-up duringalignment due to friction can relax over time with small vibrations orchanges in temperature, causing drift of probe position. Mechanisms atindividual sites, along with the height of two rods, limit microscopeworking distance. Probe card access from underneath can be cumbersome.Double-sided wedge card that probes multiple die works for one diespacing.

In U.S. Pat. No. 7,436,171, the use of individual probe sites on railsis shown, with the rail position providing gross positioning in one XYaxis and with position of the site on the rail providing the other grossXY position. Each site has four fine position adjustments in X, Y, Z andabout one axis. A tilting feature enables access to the probe cards forreplacement from above. This design has several drawbacks. The site/railand rail/platen interfaces rely on linear bearing trucks and rails. Thetrucks are elastically preloaded, which limits their stiffness. Carefulmatching during manufacture can improve stiffness, but can make itdifficult to add trucks to the rails in the future. Additionally,position is controlled by a balance of forces that can change readilywith changes in temperature of system components. Another issue with thedesign is access to probe cards. Tilting of the rail to change probecards requires space. In a closely-spaced array with parallel rails, itmay be necessary to move multiple rails to access one bad card on onerail. Space constraints drive the need for a relatively thin rail thatcan readily deflect under low loads. A soft touch may be needed to keepthe rail from deflecting during site adjustments, depending on forexample the span between platen guides. Additionally, the height of thefine positioning mechanism can limit microscope working distance andoptical resolution.

In U.S. Pat. No. 8,402,848, versatile probe modules on positioner arms,where 3-axis positioners have bases that tilt in one or two axes. Thearms cover a lot of the wafer, limiting the number of sites that can betested simultaneously. The arms are different shapes. Over temperaturechanges, the arms may distort differently. Probe module planarizationadjustments provided by the tilt bases are offset from the probes, whichcan cause large changes in Z at the probes and which can have differentbehavior for different arm types.

SUMMARY

This disclosure generally relates to a multi-site precision positioningmechanism, and more particularly, to systems, apparatuses, and methodsfor positioning multiple probe arrays for device(s) under test (DUT),e.g. the testing of semiconductor devices in a semiconductor wafer, overa wide temperature range.

Embodiments disclosed herein relate generally to systems, apparatuses,and methods which are suitable in enclosed environments that can controllight, atmosphere and/or electromagnetic interference. Test temperaturesof a DUT, e.g. a wafer, can range from −65 to 300 C and higher. Sometests have measurements at multiple temperatures. The systems,apparatuses, and methods herein can finely align multiple sites and atdesired temperatures and ranges. The systems, apparatuses, and methodsherein can provide a controlled environment to minimize thermalperturbations or the impact thereof, which may cause probes to drift outof alignment, such as when the system returns to thermal equilibrium.

The systems, apparatuses, and methods herein can provide a multi-sitepositioning mechanism suitable for long-term testing of a DUT (e.g.semiconductor wafers) across a range of temperatures with or without acontrolled environment. The systems, apparatuses, and methods herein canprovide excellent mechanical stability, permit relatively close workingdistance optics with high resolution, enable fine positioning atelevated temperature in a controlled environment with minimal thermalperturbation. The systems, apparatuses, and methods herein can beprovided with modularity, for example as modular components, for examplewith rails and test sites that can be easily added or removed, and thatcan permit access to probe modules in a densely packed array.

The systems, apparatuses, and methods herein can provide for multi-sitetesting of semiconductor wafers, the benefits of which include easyadjustment to different wafer layouts and performance of tests over awide range of temperatures.

The Detailed Description below refers to the drawings and describesembodiments of features of the systems, apparatuses, and methods herein,while the aspects that follow provide examples of general recitations ofsuch features.

DRAWINGS

These and other features, aspects, and advantages of the will becomebetter understood when the following detailed description is read withreference to the accompanying drawings, wherein:

FIG. 1 shows a perspective view of an embodiment of a multi-sitepositioning mechanism.

FIG. 2 shows a partial close-up and perspective view of the multi-sitepositioning mechanism and of an embodiment of an interface of a frame ofthe multi-site positioning mechanism with a prober platen insert.

FIG. 3 shows a close-up and perspective view of an embodiment of a clampas a component of a bracket assembly of the multi-site positioningmechanism that mounts and positions rails of the multi-site positioningmechanism to the frame of the multi-site positioning mechanism.

FIG. 4 shows a close-up and perspective view of an embodiment of abracket body of a bracket assembly of the multi-site positioningmechanism and showing contacts between the bracket body and the frame,and contacts for mounting the rail to the bracket body.

FIG. 5A shows a close-up and perspective view of an embodiment of abracket assembly incorporating the clamp of FIG. 3 and the bracket bodyof FIG. 4, and showing an embodiment of a retention cap to retain therail (partially shown) to the bracket body. FIG. 5B also shows aclose-up and perspective transparent view of an embodiment of a bracketassembly incorporating the clamp of FIG. 3 and the bracket body of FIG.4, and showing an embodiment of a retention cap to retain the rail(partially shown) to the bracket body.

FIGS. 6A and 6B show a close-up and perspective view of an embodiment ofa site assembly with probe module installed, as shown from near (onleft) and far (on right) sides of a rail, respectively. FIG. 6C shows anembodiment of a site assembly showing connector, cable paths.

FIG. 7A shows a perspective view of an embodiment of an enclosure with asliding plate and small access port for a lifting tool. FIG. 7B shows aperspective view of another embodiment of an enclosure.

FIG. 8 shows a perspective view of an embodiment of a multi-sitepositioning mechanism with multi-site and multi-rail.

FIG. 9A shows a perspective view of an embodiment of a fine adjustmenttool. FIG. 9B shows another perspective view of the fine adjustment toolof FIG. 9A.

FIG. 10 shows a perspective view of a tool lift.

DETAILED DESCRIPTION

Embodiments disclosed herein relate generally to a multi-site precisionpositioning mechanism, and more particularly, to systems, apparatuses,and methods for positioning multiple probe arrays for device(s) undertest (DUT), e.g. the testing of semiconductor devices in a semiconductorwafer, over a wide temperature range.

Embodiments disclosed herein relate generally to systems, apparatuses,and methods which are suitable in enclosed environments that can controllight, atmosphere or electromagnetic interference. Test temperatures ofa DUT, e.g. a wafer, can range from −65 to 300 C and higher. Some testshave measurements at multiple temperatures. The systems, apparatuses,and methods herein can finely align multiple sites and at desiredtemperatures and ranges. The systems, apparatuses, and methods hereincan provide a controlled environment to minimize thermal perturbationsor the impact thereof, which may cause probes to drift out of alignment,such as when the system returns to thermal equilibrium.

The systems, apparatuses, and methods herein can provide a multi-sitepositioning mechanism suitable for long-term testing of a DUT (e.g.semiconductor wafers) across a range of temperatures with or without acontrolled environment. The systems, apparatuses, and methods herein canprovide excellent mechanical stability, permit relatively close workingdistance optics with high resolution, enable fine positioning atelevated temperature in a controlled environment with minimal thermalperturbation. The systems, apparatuses, and methods herein can beprovided with modularity, for example as modular components, for examplewith rails and test sites that can be easily added or removed, and thatcan permit access to probe modules in a densely packed array.

The systems, apparatuses, and methods herein can provide for multi-sitetesting of semiconductor wafers, the benefits of which include easyadjustment to different wafer layouts and performance of tests over awide range of temperatures.

FIG. 1 shows a perspective view of an embodiment of a multi-sitepositioning mechanism. The multi-site positioning mechanism is shownwith one rail 400 and one probe site 500. It will be appreciated thatthe multi-site positioning mechanism may be configured to carry multipleprobe sites on the rail 400 and/or include multiple rails 400 each withone or more probe sites thereon, and where multiple mounting componentssuch as bracket assemblies (further described below and shown in FIG. 8)may be employed to assemble the rails as part of the multi-sitepositioning mechanism.

In an embodiment, the multi-site positioning mechanism may also includean enclosure (shown in FIGS. 7A and 7B) and/or a tool lift (shown inFIG. 10).

In FIG. 1, an embodiment of a prober platen insert 100, which may bedesigned for a specific prober, is mounted to a prober platen which maybe a frame to hold the prober platen insert 100, for example a suitableplate or platform onto or into which the prober platen insert 100 may besuitably mounted. In an embodiment, the prober platen insert 100 is madefrom the same material as the prober platen. In such a case, shiftingcan be minimized between prober platen insert 100 and the prober platenover changes for example in tests or environmental conditions such asfor example temperature.

In an embodiment, a frame 200 mounts to the prober platen insert 100. Inan embodiment, the frame 200 is rectangular and the like, but it will beappreciated that the frame 200 may be other shapes as suitable and/ordesired. In an embodiment, the frame 200 provides a flat plane on a topface 201. In an embodiment, the top face 201 is parallel to a wafer 9.In an embodiment, the wafer 9 is supported and positioned by a proberchuck. In an embodiment, the frame 200 includes two parallel faces 202,203.

In an embodiment, bracket assemblies 301, 302 contact the frame 200 topface 201, and one of the faces 202, 203. As shown, two bracketassemblies 301, 302 are on the frame 200 to mount a rail 400. It will beappreciated that more bracket assemblies may be employed as additionalrails 400 are mounted to the frame 200.

In an embodiment, the rail 400 is supported by the bracket assemblies301, 302.

In an embodiment, a site assembly 500 mounts to the rail 400. One siteassembly 500 is shown, however, it will be appreciated that the rail 400and/or additional rails like rail 400 for example may include additionalsite assemblies 500.

In an embodiment, a probe tile assembly 600 mounts to the site assembly500. It will be appreciated that interconnect cables, guides, paths (seee.g. FIG. 6C) are employed as needed for example to provide suitableelectrical connections.

In an embodiment, a fine adjustment tool assembly 700 interfaces to thesite assembly 500 and includes a microscope assembly 710.

For purposes of the description, the Z axis is perpendicular to thewafer 9, the Y axis runs parallel along the length of the frame faces202 and 203 and perpendicular to the Z axis, and the X axis isperpendicular to the Y and Z axes.

In an embodiment of use, a probe module 600 is mounted to the siteassembly 500 and the fine adjustment tool assembly 700 is mounted to thesite assembly 500. The brackets 301, 302 slide along the frame 200 forgross Y positioning and can be clamped to the frame 200. The siteassembly 500 slides along the rail 400 for gross X positioning and canbe clamped to the rail 400. The microscope tool assembly 710 providesvisual feedback during positioning. Once gross positioning is complete,the fine adjustment tool assembly 700 can actuate positioning mechanismsin the site assembly 500 for fine X, Y, Z and rotation of the probemodule 600 about the Z axis.

In an embodiment, for installations with multiple sites, e.g. siteassemblies 500 and/or with multiple rails 400, the tool assembly 700 canbe moved from site to site without altering the position of the sites.In an embodiment, gross positioning is performed during initial setup atambient temperature. In an embodiment, fine positioning is performed attest temperature, after the system has reached thermal equilibrium.

In an embodiment, for applications in a dark or shielded environment,the tool assembly 700 can be inserted through a small port of anenclosure (shown in and described below with respect to FIGS. 7A and7B), which can minimize perturbations to thermal equilibrium. In anembodiment, for applications requiring a fully controlled environment, atool lift which may be a motorized tool, which may include a gantry canbe used to lift and move the tool from site to site, so it can make thefine adjustments.

An advantage of this system is the ability of the tool to move from siteto site without disturbing the positions of the probe modules mounted tothe sites. In an embodiment, this capability is enabled by thecombination of high rigidity system components, a site assembly 500design that couples tool loads directly to the rail 400 while isolatingthe probe module 600, and a unique kinematic design that provides exactconstraint for most system components while ensuring the probe tips donot drop in Z if kinematic contacts are separated.

For a detailed discussion of “exact constraint”, see “Exact constraint:Machine design using kinematic principles” by Douglass L. Blanding, ASMEPress, 1999. In short, a three dimensional body has 6 degrees offreedom, motion in the X, Y and Z directions as well as rotation aboutthese three axes. With exact constraint design, these degrees of freedomare controlled with 6 constraints. In the case of the multi-sitepositioning mechanism herein, these constraints can take the form ofcontact points or small contact pads between components. A nesting forcekeeps each pair of contacts mated. In the contact direction, theinterface in an embodiment is relatively rigid and repeatable. Over widetemperature ranges, as components change size, nesting forces determinecontact forces. A potential disadvantage of kinematic contacts is that acontact between two components separate when a counter force greaterthan the nesting force is applied (in a direction opposite the nestingforce). Though the component will return to its' original position whenthe counter force is removed, it is of little benefit if separation ofthe contact drives the probes into the wafer, damaging them. Thecrash-resistant kinematic contact arrangements described in more detailbelow can help provide reliable use of an exact constraint design.

FIG. 2 shows a partial close-up and perspective view of the multi-sitepositioning mechanism of FIG. 1 and of an embodiment of a kinematicinterface of a frame of the multi-site positioning mechanism with aprober platen insert.

In an embodiment, the prober platen insert 100 has three (3) vees, forexample made from pairs of parallel cylinders 209, which are orientedtoward the center of the prober platen insert 100. In an embodiment, theframe 200 has three (3) adjustment screws 205 with ball ends 211 thatalign with the vees. In an embodiment, lock nuts or the like on theadjustment screws 205 lock the adjustment screws. In an embodiment, ahold-down screw 207 or the like is located near each adjustment screw205 to prevent the frame 200 from falling off the prober platen insert100 in the event there is a high force applied to the frame (e.g. anearthquake). In an embodiment, the hold down screws 207 may include acompression spring 213. FIG. 1 shows the three sets of adjustment screws205 and hold-down screws 207 for three interface regions between theprober platen insert 100 and the frame 200. FIG. 2 shows one of thethree interface regions between the platen insert 100 and the frame 200.In an embodiment, the kinematic interface formed by the three interfaceregions form a Kelvin clamp kinematic interface, with three balls inthree vee grooves.

FIG. 3 shows a close-up and perspective view of an embodiment of a clamp303 as a component of a bracket assembly of the multi-site positioningmechanism that mounts and positions rails 400 of the multi-sitepositioning mechanism to the frame 200 of the multi-site positioningmechanism.

In FIG. 3, an embodiment of a bracket-frame kinematic interface is shownby way of an exemplary clamp mechanism. With reference to FIG. 1, rail400 is supported by a bracket assembly 301, 302 at each end. In anembodiment, the bracket assemblies 301, 302 each contain a clamp 303that wraps around the edge of the frame 200, e.g. around the faces 201,202 or 203, and the bottom of the frame 200. In an embodiment, two balls305 bonded into the lower part of the clamp 303 slide along a groove215, e.g. shown as a V groove, in the bottom face of the frame 200. Inan embodiment, when the clamping screw 311 is tightened, the clamp 303grips the frame 200 tightly. The clamp 303 has two perpendicular faces307, 309 that are also generally parallel to the XZ plane. A springplunger 304 in the bracket pushes the clamp against a ball contact 306and contact location 318 in the bracket 315 (see FIG. 4). When the clamp303 is loosened, it slides along with the bracket assembly 301, 302 asit is moved. When the clamp 303 is tightened, it restricts motion of thebracket assembly 301, 302 in the Y direction. In an embodiment, theclamp 303 restricts motion of the bracket assembly 301, 302 withoutsignificantly preventing other motion of the bracket assembly overrelatively small displacements.

In an embodiment, the clamp 303 is in the bracket body 315 (see e.g.FIGS. 5A and 5B). FIG. 4 shows a close-up and perspective view of anembodiment of a bracket body 315 of a bracket assembly 301, 302 of themulti-site positioning mechanism and showing contacts between thebracket body 315 and the frame 200, and contacts for mounting the rail400 to the bracket body 315. FIG. 4 shows an embodiment of arail-bracket kinematic interface, with an embodiment of contacts betweenthe rail 400 and bracket body 315.

In an embodiment, the bracket body 315 contacts the frame 200 forexample at five contact pads made from a polymer bearing material. In anembodiment, contacts Z1, Z2, and Z3 restrict motion of the bracket inthe Z direction. In an embodiment, about the X and Y axes, contacts X1and X2 restrict motion in the X direction and about the Z axis. Theclamp 303, spring plunger 304 and ball 306 shown in FIG. 3 are omittedfrom FIG. 4 for clarity. It will be appreciated that bracket assembliescan be added and removed from the frame 200.

For purposes of description, the bracket body 315 is shown in atransparent view relative to its features/contacts and the frame 200. Inan embodiment, an oval-tipped screw 319 (see e.g. FIG. 5A) passingvertically through each end of the rail 400 lands on the bracket atlocation Z4 of the bracket body 315 to control the Z position of the endof a rail 400. In an embodiment, the screw 319 can be adjusted toplanarize the top of the rail 400 to the DUT array. At one end of therail 400, adjustable contact M1 and fixed ball contact M2 contact thetwo faces of the rail 400, preventing it from rotating about the X axis.A ball contact X3 contacts the rail 400 at the end, preventing it frommoving in X.

In an embodiment, a screw 317 inserts through the bracket body 315 tofix the rail 400 for example in YZ (see e.g. FIGS. 4, 5A, and 5B).

At the other end of the rail 400, in an embodiment, a spring plunger canreplace the X3 contact and the M1 contact can be omitted. Spring forcefrom the plunger keeps both brackets against their X1 and X2 contactsand the rail against the X3 contact.

FIG. 5A shows a close-up and perspective view of an embodiment of abracket assembly incorporating the clamp of FIG. 3 and the bracket bodyof FIG. 4, and showing an embodiment of a retention cap 321 to retainthe rail (partially shown) to the bracket body. It will be appreciatedthat FIG. 5A resembles the bracket assembly 301 of FIG. 1, whichincludes the clamp 303, bracket body 315 and their respective componentsdescribed above relative to FIGS. 3 and 4. However, the bracket assemblyshown in FIG. 5A is the mirror image of the orientation of the clamp 303and bracket body 315 shown in FIGS. 3 and 4, which are of the bracketassembly 302 in FIG. 1.

Further shown in FIG. 5A, in an embodiment, the retention cap 321rotates, for example about a screw 325, and can be fixed to the bracketbody 315 with a screw 323. It will be appreciated that bracketassemblies 301, 302 have a cap (see e.g. FIG. 1), where one cap 321 isshown in detail in FIG. 5A. In the fixed position, the cap 321 in anembodiment retains the rail 400 so it does not lift very far off thebracket body 315. In an embodiment, the cap 321 contains a ball plunger329 that biases the rail 400 against contacts M1 and M2. A pin 327 inthe cap nests in a feature 402 in the rail 400. If one of the caps 321is open on one end of the rail 400 and the other cap is fixed, the rail400 can be lifted at the open end to add or remove site assemblies 500.The pin 327 and rail feature 402 at the fixed end prevent the rail 400from pulling out. Either end of the rail 400 can be lifted for siteassembly access, or the entire rail can be lifted off if both caps 321are open.

FIG. 5B also shows a close-up and perspective transparent view of anembodiment of a bracket assembly incorporating the clamp of FIG. 3 andthe bracket body of FIG. 4, and showing an embodiment of a retention cap321 to retain the rail (partially shown) to the bracket body. FIG. 5Bresembles the bracket assembly 302 of FIG. 1, which includes the clamp303, bracket body 315, the retention cap 321, and their respectivecomponents described above relative to FIGS. 3, 4, and 5A. The bracketassembly shown in FIG. 5B includes the clamp 303 and bracket body 315shown in FIGS. 3 and 4 describe above and assembled together with theretention cap 321, but is the mirror image of the orientation of thebracket assembly shown in FIG. 5A. It will be appreciated that thedashed lines would be hidden when the view is not transparent.

FIGS. 6A and 6B show a close-up and perspective view of an embodiment ofa site assembly 500 with probe module 600 installed, as shown from near(on left) and far (on right) sides of a rail, respectively. In anembodiment, FIGS. 6A and 6B show a site-rail kinematic interface. In anembodiment, the site assembly 500 has an upper portion 502 and a lowerportion 504. In an embodiment, the upper portion 502 includes a saddle506, upper clamp 508, isolators 510 that can be driven with a tool andfeatures for joining with the tool in a kinematic clamp. In anembodiment, the lower portion includes a lower clamp 512 and a carriageassembly 514 with X, Y, Oz fine positioning stage driven by screws. Inan embodiment, a screw 516 between the upper and lower clamps isloosened to move the site along the rail. In an embodiment, a springbiases the saddle against the upper clamp in X. In an embodiment, whenthe screw 516 between the clamps 508, 512 is tightened, the clamps 508,512 rigidly grip the rail 400 and prevent the site 500 from moving in X.In an embodiment, when the clamping screw 516 is loosened, the siteassembly moves freely along the rail 400.

In an embodiment, the saddle 506 has two contacts with the top of therail, one contact near the top of the rail on the vertical face near theprobe module (near side) and two contacts toward the bottom of the railon the other vertical face (far side). In an embodiment, two verticalextension springs 518 between the saddle 506 and upper clamp 508 apply amoment to the saddle that keeps the near and far contacts against therail.

In an embodiment, the carriage 514 has two contacts against the nearside of the rail near the bottom and one contact on the far side nearthe top. In an embodiment, two extension springs between the carriageand lower clamp 512 apply a moment that keeps the contacts against therail. In an embodiment, on the far side, there are two contacts 528, 532between the carriage 514 and saddle 506. In an embodiment, a verticalextension spring 520 between the carriage and saddle pulls down on thecarriage. In an embodiment, this spring is also located off center in Xso that it applies a moment about the Y axis that keeps the twocarriage/saddle contacts engaged.

In an embodiment, a differential screw 534 on the far side of the rail400 controls the Z position of the carriage 514. In an embodiment, thescrew 534 has coarse threads on the top half and fine threads in thebottom half. In an embodiment, the coarse portion of the screw 534engages a ball 530 with threaded hole that rests in an upward facing 60degree countersink. In an embodiment, the fine portion of the screw 534engages a ball 536 with a threaded hole that is in a downward facing 60degree countersink in the carriage. In an embodiment, when thedifferential screw 534 is turned clockwise (when observed from above),it advances down at a higher rate while the lower ball 536 rises up thescrew at a lower rate, resulting in the carriage moving down at a verylow rate. In an embodiment, hex shafts 524 extend from the stage drivescrews to the isolators 510 that are driven by the tool to enable thecarriage to move in Z while the tool interface remains at the samelevel.

In an embodiment, the location of the differential screw 534 on the farside of the rail 400, in combination with the contact arrangementdescribed minimizes the risk that the probe module 600 will be damagedif any of the contact restraints are overpowered and a contactseparates. In an embodiment, if excessive force is applied to the nearside of the saddle 506, the saddle 506 may tip down on the near side. Inan embodiment, with the differential screw 534 on the far side, this canraise the carriage 514 and probe module 600. Similarly, when thecarriage 514/rail 400 or carriage 514/saddle 506 contacts are lifted,the probe module 600 may be lifted.

In an embodiment, a tool-site kinematic interface includes three buttonhead screws 526 at the top of the saddle 506 engage in three vee grooveson the underside of the tool 700, forming a very repeatable kinematicclamp. In an embodiment, the screws can be adjusted to set tool heightand to center the probes in the microscope field of view and have jamnuts to lock their positions. In an embodiment, one or more magnets inthe tool 700 and/or site assembly 500 can assist in restraining thetool/site contacts. In an embodiment of use, the tool 700 is set on thesite assembly 500.

FIG. 6C shows an embodiment of a site assembly resembling site assembly500 and also showing connector, cable paths. Site assembly 500 are shownwith an embodiment of cable path regions 650, 660. In an embodiment, theprobe module 600 can have 20-50 individual cables attached to it thatare connected to individual probes. In some cases, two cables areconnected to each probe for kelvin measurements. In an embodiment,cables are electrically insulated from one another and may be eithersingle conductor, coaxial or other configurations such as twisted pairor strip line. In an embodiment, cables connect the probes to testinstrumentation. For ease of use, for example, the cables permanentlyattached to the probe modules are about 1 meter in length. In anembodiment, additional cable extensions, switch matrices, patch panelsand other electrical interconnect devices may be in the electrical pathbetween the probe module and test instrumentation.

Cables are guided from the probe module 600 by the curved upper portionof the saddle 506 along paths 650. Note the paths 650 are intended toapproximate the boundaries of multiple individual wires. Guiding thecables along paths 650 helps ensure the region directly above the probemodule 600 remains clear for a microscope. Toward the top of the siteassembly, the cable paths 650 merge into a rectangular cable path 660defined by the saddle 506 and cable cover 538. The cable cover 538 helpsensure cables do not protrude above the site assembly. Cables from theprobe module 600 can be routed to either side of the site assembly 500so as to be guided to the closest end of the rail 400. The rectangularcable path 660 may carry cables from several probe modules.

FIG. 7A shows a perspective view of an embodiment of an enclosure 800with a sliding plate 802 and small access port 804 for a lifting tool tomanipulate tool assembly 700. In an embodiment, for applications in adark, shielded, and/or dry environment, enclosure 800 with one or moresliding plates 802 on the top can be added to the system. Shown in FIG.7 is a single sliding plate that can be slid or rotated with access port804 located off-center. In an embodiment, several successively smallerplates with successively smaller access ports/holes in their center maybe employed. In an embodiment, the plate(s) 802 enable a small accessport(s) 804 to be positioned over any site 500 location. In anembodiment, a cover 806 blocks the access port 804 when the tool 700 isnot in place. In an embodiment, a window 808 in the cover 806 permitsthe port 804 to be aligned to a site without opening it and the tool 700blocks the port 804 when in place to minimize thermal perturbations whenoperating at elevated temperatures, or to minimize moisture whenoperating at low temperatures. In an embodiment, sidewalls 810 in theenclosure 800 are removable and can be replaced with interface panelsfor routing electrical signals through the enclosure walls. In anembodiment, the enclosure top is removable for system setup and grossalignment.

In an embodiment, tool lift (see e.g. FIG. 10), or the like can includea lift mechanism which can be placed on top of the enclosure 800 slidingplates or supported by a gantry, or arm(s), or suitable mechanism. In anembodiment, the tool lift is pneumatic, with a pneumatic cylinderpulling the tool down at a controlled rate. In an embodiment, when theair is turned off, an extension spring returns the tool to the raisedposition. This arrangement would ensure the tool does not drop if airpressure is lost. In an embodiment, stroke of the lift is enough tocompletely remove the tool 700 from the enclosure 800 so the access port804 can be closed when the tool 700 is in the raised position. A damperin the lift or tool 700 can further reduce approach speed to minimizeimpact force on the site assembly. Some of the weight of the tool 700can be supported by the lift or enclosure 800 in the down position viacompression springs.

FIG. 7B shows a perspective view of another embodiment of an enclosure.For example, in applications in a dark, shielded and/or dry environment,an enclosure 800 with one or more sliding plates on the top can be addedto the system. Shown in FIG. 7B is a single sliding plate 802 that canbe slid or rotated with an access port 804 located off-center. The port804 includes a hole in an alignment disc 806 that is slightly largerthan the tool base 701 (see e.g. FIGS. 9A and 9B). An alternative isseveral successively smaller plates with successively smaller holes intheir center. In either case, the plates enable the small access port tobe positioned over any site location. Different from FIG. 7A, in anembodiment, a cover assembly 820 blocks the access port when the tool700 is not in place. In and embodiment, a window 821 in the coverassembly 820 permits the port 804 to be aligned to a site 500 withoutopening it and a pivoting shade 822 can be pivoted over the window 821during testing for light sensitive measurements. In an embodiment, thetool 700 or cover assembly 820 blocks the port 804 to minimize thermalperturbations when operating at elevated temperatures, or to minimizemoisture when operating at low temperatures. In an embodiment, thesliding plate 802 slides on a top plate 830, which is supported by posts831, 832. In an embodiment, the posts are mounted to a bottom plate 833,which is mounted to the prober platen 102. In an embodiment, sidewalls810 in the enclosure are removable and can be replaced with interfacepanels for routing electrical signals through the enclosure walls. In anembodiment, the entire enclosure top (830, 802, 806, 820) is removablefor system setup and gross alignment.

FIG. 8 shows an embodiment of a multi-site positioning mechanism withmulti-sites 500 and multi-rails 400. Similar features as in FIG. 1 areshown including bracket assemblies 301, 302, the prober platen insert100 assembled with a probe platen 102, as well as the frame 200 andprobe modules 600. In FIG. 8, system assembly is shown withoutenclosure, tool lift, or cables. Probe platen 102 is shown, which mayalso be known as a prober head plate.

In an embodiment, the multi-site, multi-rail configuration shows fivesites per rail, showing three rails for a three rail by five site (15sites) configuration.

It will be appreciated that the tool 700 can be moved to any of thesites 500, and that an enclosure, e.g. enclosure 800, can encloseconfiguration.

FIG. 9A shows a perspective view of an embodiment of a fine adjustmenttool 700. FIG. 9B shows another perspective view of the fine adjustmenttool of FIG. 9A.

In FIG. 9A, tool 700 includes in an embodiment a base plate 701 withcontrol knobs 702 for fine XYZ adjustments, theta adjustment, microscopemovement and/or focusing, clamping knob 704, and an optical assembly(710, 711, 712, 713). It will be appreciated that more or less knobsthan shown may be employed as desired and/or suitable. In an embodiment,the control and clamping knobs 702, 704 are free to rotate in the baseplate 701 and may have a little play so they can move side to side asmall distance a. Extending from the bottom of the knobs are hexagonaldrive shafts 703 that engage with isolator assemblies in the siteassembly when the tool is lowered on a site. The clamping knob 704 canbe removed after site assemblies 500 have been grossly aligned. Themicroscope assembly includes a tube microscope body 710, a video camera711, a microscope light 712 and microscope objective 713.

In FIG. 9B, the bottom of the base plate 701 is shown. In an embodiment,the tool 700 includes three vees made from pairs of dowel pins 705bonded into the base plate 701. When the tool 700 is placed on a siteassembly 500, convex surfaces on the site 500 engage with the vees toform a Kelvin clamp kinematic interface. The small amount of play in theknobs ensures the kinematic interface controls position of the tool 700.Also visible from the bottom are three pockets 706 that engage with thetool lift (see FIG. 10) as it rises.

FIG. 10 shows a perspective view of an embodiment of a tool lift. In anembodiment, a lift mechanism 900 can be placed on top of the enclosuresliding plates 802, 830 (see FIG. 7B) in place of the alignment disc 806and/or supported by a gantry or arm. In an embodiment, the tool liftincludes a base plate 901 that supports two linear shafts 902, whichterminate at a top plate 903. In an embodiment, a cradle assembly 910has rollers 905, bushings or other linear motion elements that restrainmotion to the Z direction. In an embodiment, the cradle assembly 910carries the tool 700 when the tool 700 is not nested with a siteassembly 500. In an embodiment, when the tool 700 is nested with a siteand the lift is in the down position, the cradle assembly 910 does notcontact the tool 700. In an embodiment, the tool lift is pneumatic, witha pneumatic cylinder 904 pulling the tool down at a controlled rate. Inan embodiment, when the air is turned off, an extension spring returnsthe tool to the raised position. This arrangement can ensure that thetool does not drop if air pressure is lost. In an embodiment, stroke ofthe lift is enough to completely remove the tool from the enclosure sothe access port can be closed with a cover assembly 920 when the tool isin the raised position. A window 921 in the cover enables aligning thelift with a site without leaving the access port 804 open. A shutter 922in the cover can be closed to cover the window for light sensitivemeasurements. It will be appreciated that FIG. 10 shows a similar butdifferently shaped cover assembly than cover assembly 820. In anembodiment, a damper in the lift or tool can further reduce approachspeed to minimize impact force on the site assembly. In an embodiment,some of the tool weight can be supported by the lift or enclosure in thedown position via compression springs.

X, Y and Z directions are arbitrary and based on the convention of an XYplanar array approached in the Z direction. Likewise, “above” is in theZ direction from which the DUT array can be observed and tested. Nothingin this disclosure should be taken to limit orientation of these X, Yand Z directions in 3-d space. For example, if the DUT array is in avertical plane, “above” could be to the left or right of the array,depending on orientation.

Aspects

The aspects below describe in general terms features and elementsdescribed above with respect to FIGS. 1-8. It will be appreciated thatany of the following aspects 1-28 may be combined with any of the listedaspects.

Aspect 1. A probe module positioning system to observe and test arraysof devices under test (DUT) comprising:

a support member including:

-   -   a planar surface parallel to array, and    -   two linear guide features that are parallel to a direction (Y)        of the DUT array, the guide features being separated in a        direction (X) that is perpendicular to the direction (Y) so that        the DUT array is disposed therebetween;

at least two brackets supported in a direction (Z) by the planar surfaceof the support member, the direction (Z) being perpendicular to thedirection (X) and the direction (Y), the at least two brackets beingmovable along the two linear guide features in the direction (Y) andconfigured to be restricted from moving along the guide features andfrom moving perpendicular to the guide features in at least onedirection relative to the direction (Y), with at least one of thebrackets guided by one of the two linear guide features such that atleast one of the brackets is disposed on a side of the DUT array;

at least one rail supported above the DUT array at each end by the atleast two brackets, the at least two brackets being disposed on oppositesides of the DUT array such that the rail can be positionedperpendicular to the two linear guide features and parallel to thedirection (X), the at least two brackets controlling a position of theends of the rail in the direction (Y) and the direction (Z) and at leastone of the brackets also controlling a position of the rail in thedirection (X) and at least one of the brackets controlling rotation ofthe rail about a longitudinal axis of the rail;

at least one site assembly that can carry a probe module and that isprevented from moving in at least one of the direction (Y) and thedirection (Z) and about (X), (Y), and (Z) axes in at least one directionof the rail, the at least one site assembly being positioned along therail, the at least one site assembly can be restricted from moving alongthe rail, the site assembly including at least one fine positioningstage for positioning the probe module relative to the site assembly inthe direction (X), the direction (Y), or the direction (Z), or about the(X), (Y), or (Z) axes; and

a tool that includes optics for viewing a DUT, a control, or an actuatorfor at least one site assembly fine positioning axis, that can bealigned with the site assembly to actuate at least one fine positioningstage in the site assembly.

Aspect 2. The system of aspect 1, wherein the support member is arectangular plate supported by a platen insert which can be planarizedrelative to the DUT array.

Aspect 3. The system of aspect 2, wherein the planarization is providedby three ball end screws engaged in threaded holes in the plate, theball ends nesting in three vee grooves or pairs of parallel cylindricalfaces in the prober platen insert, thereby forming a kinematic clampbetween the support member and platen insert.

Aspect 4. The system of any one of aspects 2-3, wherein the supportmember has a rectangular hole in a center of the support member,creating a frame shape, with two parallel vertical faces of the holebeing the guide features.

Aspect 5. The system of any one of aspects 1-4, wherein each bracket hasthree contacts against the planar surface of the support member and twocontacts against one of the guide features.

Aspect 6. The system of aspect 5, wherein the bracket contacts are heldagainst their respective guide features by a force normal to the guidefeatures and generally along the length of the rail (X axis), with therail taking part in transmitting the force between the two brackets.

Aspect 7. The system of any one of aspects 1-6, wherein each bracket isspring-biased against a clamp which does not interfere with bracketmotion when loosened and which restrains bracket motion along the guidefeatures when tightened, but does not interfere with the other 5 degreesof freedom of the bracket.

Aspect 8. The system of any one of aspects 1-7, wherein each siteassembly is spring-biased against a clamp which does not interfere withsite assembly motion when loosened and which restrains site motion alongthe rail when tightened but does not interfere with the other 5 degreesof freedom of the site assembly.

Aspect 9. The system of any one of aspects 1-8, wherein the tool mateswith the site assembly in a kinematic clamp and can be moved from siteassembly to site assembly.

Aspect 10. The system of aspect 9, wherein the support member, brackets,rails, and site assemblies are in an enclosure, with the platen insertforming a bottom side of the enclosure, the enclosure having a top sidehaving one or more sliding plates to permit an access port to bepositioned over any location where the site assembly can be positioned,the access port can be opened or closed.

Aspect 11. The system of aspect 10, wherein the access port is largeenough to allow the tool to mate with the site assembly.

Aspect 12. The system of aspect 11, wherein the tool substantially sealsthe access port when in place to minimize airflow in or out of theenclosure.

Aspect 13. The system of any one of aspects 1-12, further comprising atool lift to raise and lower the tool.

Aspect 14. The system of aspect 12, further comprising a tool lift toraise and lower the tool, the tool lift being supported by the slidingplates, in an up position, the tool is outside of the enclosure and theaccess port can be closed, and in the down position, the tool mates withthe site assembly.

Aspect 15. The system of aspect 13, wherein some of the tool weight iscarried by the tool lift in the down position.

Aspect 16. The system of any one of aspects 1-15, wherein the rail has arectangular cross-section and is oriented so that major surfaces of therail are perpendicular to the DUT array.

Aspect 17. The system of any one of aspects 1-16, wherein the probemodule is mounted to the site assembly on one side of the rail, accessto the probe module for installation or removal also serves as toolmicroscope access when the tool is in use at the site assembly.

Aspect 18. The system of any one of aspects 1-17, where the siteassembly has upper and lower portions, the upper portion interfaces withthe tool and supports the lower portion in the direction (Z) andprevents the lower portion from rotating about the (Y) axis, and thelower portion supports the probe module.

Aspect 19. The system of aspect 18, wherein the upper portion is clampedto the rail.

Aspect 20. The system of any one of aspects 18-19, wherein the upperportion is biased against the clamp.

Aspect 21. The system of any one of aspects 18-20, wherein the upperportion has two contacts against a top of the rail that keep the siteassembly from dropping in the direction (Z) or rotating about the (Y)axis, two contacts spaced horizontally against one side of the rail, andone contact against the other side of the rail, contacts on one side ofthe rail are disposed relatively toward the top of the rail relative tothe bottom of the rail and contacts on the other side of the rail aredisposed relatively toward the bottom of the rail relative to the top ofthe rail, the lower portion is located on the side of the rail with thelower contacts.

Aspect 22. The system of any one of aspects 18-21, wherein the lowerportion is adjustable, enabling the lower portion to be moved in thedirection (Z), wherein fine positioning mechanisms in the lower portionare actuated rotationally, with a sliding coupling transmitting torquewhile allowing vertical motion.

Aspect 23. The system of aspect 22, wherein the lower portion has twocontacts spaced against one side of the rail and one contact against theother side of the rail.

Aspect 24. The system of any one of aspects 1-23, wherein the bracketshave pivoting caps that retain the end of the rail when secured andenable the rail to be lifted up when open.

Aspect 25. A system, comprising:

the probe module positioning system to observe and test arrays ofdevices under test (DUT) according to aspect 1;

an enclosure, wherein the support member, brackets, rails, and siteassemblies are disposed within the enclosure; and

a tool lift disposed on a top side of the enclosure for manipulating alocation of the tool.

Aspect 26. The system of aspect 25, wherein the tool lift ispneumatically controlled.

Aspect 27. A method of positioning a probe module for observing andtesting arrays of devices under test (DUTs), the method comprising:

grossly positioning a site assembly carrying the probe module along atleast one rail, the at least one rail being supported above a DUT arrayat each end by at least two brackets, the at least two brackets disposedon opposite sides of the DUT array such that the rail can be positionedperpendicular to two linear guide features and parallel to a direction(X), the at least two brackets controlling a position of the ends of therail in the direction (Y) and the direction (Z) and at least one of thebrackets also controlling a position of the rail in the direction (X)and at least one of the brackets controlling rotation of the rail abouta longitudinal axis of the rail; and finely positioning the probe modulealong at least one of the direction (X), the direction (Y), thedirection (Z), and rotation about a (Z) axis using the site assembly,thereby positioning the probe module for test.

Aspect 28. The method of aspect 27, wherein the grossly positioning thesite assembly includes securing the at least one rail and the at leasttwo brackets in a first kinematic interface and the at least twobrackets and the two linear guide features in a second kinematicinterface.

The terminology used in this specification is intended to describeparticular embodiments and is not intended to be limiting. The terms“a,” “an,” and “the” include the plural forms as well, unless clearlyindicated otherwise. The terms “comprises” and/or “comprising,” whenused in this specification, indicate the presence of the statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, and/or components.

With regard to the preceding description, it is to be understood thatchanges may be made in detail, especially in matters of the constructionmaterials employed and the shape, size, and arrangement of parts,without departing from the scope of the present disclosure. The word“embodiment” as used within this specification may, but does notnecessarily, refer to the same embodiment. This specification and theembodiments described are examples only. Other and further embodimentsmay be devised without departing from the basic scope thereof, with thetrue scope and spirit of the disclosure being indicated by the claimsthat follow.

The invention claimed is:
 1. A probe module positioning system toobserve and test arrays of devices under test (DUT), comprising: asupport member including: a planar surface parallel to a DUT array, andtwo linear guide features that are parallel to a direction (Y) of theDUT array, the two linear guide features being separated in a direction(X) that is perpendicular to the direction (Y); a plurality of bracketssupported in a direction (Z) by the planar surface of the supportmember, the direction (Z) being perpendicular to the direction (X) andthe direction (Y), the plurality of brackets being movable along the twolinear guide features in the direction (Y) and configured to berestricted from moving along the two linear guide features and frommoving perpendicular to the two linear guide features in at least onedirection relative to the direction (Y); a plurality of rails supportedabove the DUT array, each of the plurality of rails being supported ateach end by two of the plurality of brackets, the two of the pluralityof brackets being disposed on opposite sides of the DUT array such thatthe respective rail of the plurality of rails can be positionedperpendicular to the two linear guide features and parallel to thedirection (X), the two brackets of the plurality of brackets controllinga position of the ends of the respective rail of the plurality of railsin the direction (Y) and the direction (Z) and also controlling aposition of the respective rail of the plurality of rails in thedirection (X) and controlling rotation of the respective rail of theplurality of rails about a longitudinal axis of the respective rail ofthe plurality of rails; at least one site assembly for at least one railof the plurality of rails that can carry a probe module and that isprevented from moving in at least one of the direction (Y) and thedirection (Z) and about (X), (Y), and (Z) axes in at least one directionof the at least one rail of the plurality of rails, the at least onesite assembly being positioned along the at least one rail of theplurality of rails, the at least one site assembly can be restrictedfrom moving along the at least one rail of the plurality of rails, theat least one site assembly including a carriage assembly having at leastone fine positioning stage for positioning the probe module relative tothe at least one site assembly in the direction (X), the direction (Y),or the direction (Z), or about the (X), (Y), or (Z) axes.
 2. The systemof claim 1, wherein the support member is a rectangular plate supportedby a platen insert which can be planarized relative to the DUT array. 3.The system of claim 2, wherein the planarization is provided by threeball end screws engaged in threaded holes in the plate, ball ends of thethree ball end screws nesting in three vee grooves or pairs of parallelcylindrical faces in the platen insert, thereby forming a kinematicclamp between the support member and platen insert.
 4. The system ofclaim 2, wherein the support member has a rectangular hole in a centerof the support member, creating a frame shape, with two parallelvertical faces of the hole being the two linear guide features.
 5. Thesystem of claim 1, wherein each bracket of the plurality of brackets hasthree contacts against the planar surface of the support member and twocontacts against one of the two linear guide features.
 6. The system ofclaim 5, wherein the three contacts of each bracket of the plurality ofbrackets are held against their respective guide features by a forcenormal to the two linear guide features and generally along the lengthof the at least one rail of the plurality of rails (X axis), with the atleast one rail of the plurality of rails taking part in transmitting theforce between the plurality of brackets.
 7. The system of claim 1,further comprising a tool that includes optics for viewing a DUT, acontrol, or an actuator for at least one site assembly fine positioningaxis, that can be aligned with the at least one site assembly to actuateat least one fine positioning stage in the at least one site assembly,wherein the tool mates with the at least one site assembly in akinematic clamp and can be moved from site assembly to site assembly. 8.The system of claim 7, wherein the support member, plurality ofbrackets, plurality of rails, and at least one site assembly are in anenclosure, with a platen insert forming a bottom side of the enclosure,the enclosure having a top side having one or more sliding plates topermit an access port to be positioned over any location where the atleast one site assembly can be positioned, the access port can be openedor closed.
 9. The system of claim 8, wherein the access port is largeenough to allow the tool to mate with the at least one site assembly.10. The system of claim 9, wherein the tool substantially seals theaccess port when in place to minimize airflow in or out of theenclosure.
 11. The system of claim 10, further comprising a tool lift toraise and lower the tool, the tool lift being supported by the slidingplates, in an up position, the tool is outside of the enclosure and theaccess port can be closed, and in a down position, the tool mates withthe at least one site assembly.
 12. The system of claim 1, wherein theat least one rail of the plurality of rails has a rectangularcross-section and is oriented so that major surfaces of the at least onerail of the plurality of rails are perpendicular to the DUT array. 13.The system of claim 7, wherein the probe module is mounted to the atleast one site assembly on one side of the plurality of rails, access tothe probe module for installation or removal also serves as a toolmicroscope access when the tool is in use at the at least one siteassembly.
 14. The system of claim 1, wherein the plurality of bracketshave pivoting caps that retain the ends of the plurality of rails whensecured and enable the plurality of rails to be lifted up when open. 15.A system, comprising: the probe module positioning system to observe andtest arrays of devices under test (DUT) according to claim 1; anenclosure, wherein the support member, plurality of brackets, pluralityof rails, and at least one site assembly are disposed within theenclosure; and a tool lift disposed on a top side of the enclosure formanipulating a location of a tool.
 16. The system of claim 15, whereinthe tool lift is pneumatically controlled.
 17. A method of positioning aplurality of probe modules for observing and testing arrays of devicesunder test (DUTs), the method comprising: grossly positioning aplurality of site assemblies, at least one of the plurality of siteassemblies carrying a probe module of the plurality of probe modulesalong at least one rail of a plurality of rails, the at least one railbeing supported above a DUT array at each end by a plurality ofbrackets, the plurality of brackets disposed on opposite sides of theDUT array such that the at least one rail of the plurality of rails canbe positioned perpendicular to two linear guide features and parallel toa direction (X), the plurality of brackets controlling a position of theends of the at least one rail of the plurality of rails in the direction(Y) and the direction (Z) and also controlling a position of the atleast one rail of the plurality of rails in the direction (X) andcontrolling rotation of the at least one rail of the plurality of railsabout a longitudinal axis of the at least one rail of the plurality ofrails; and finely positioning the probe module of the plurality of probemodules along at least one of the direction (X), the direction (Y), thedirection (Z), and rotation about a (Z) axis using the at least one ofthe plurality of site assemblies, thereby positioning the probe moduleof the plurality of probe modules for test.
 18. The method of claim 17,wherein the grossly positioning the plurality of site assembliesincludes securing the at least one rail of the plurality of rails andthe plurality of brackets in a first kinematic interface and theplurality of brackets and the two linear guide features in a secondkinematic interface.